Sound amplifier



Feb. 9 9 1926s C. SQRAEEC S OUND AMPLIFER Filed June a,

Patented Feb. 9, 1926.

UNITED STATES CARL SCRABIC, OF URBANA, OHIO.

SOUND AMPLIFIER.

Application filed June 6,

T 0 all whom t may concern Be it known that I, CARL SoaAisio, a citizen of the United States, residing at Urbana, in the county of Champaign and State of Ohio, have invented certain new and useful Improvements in Sound Amplifiers, of which the following is a specification.

The present invention is directed to improvements in sound amplifiers for talking machines and has for its object to provide a device of this character which when associated with the sound conducting throat will materially amplify the sound and influence the correct reproduction of the musical tones so they will be reproduced in their full value.

A further object of the invention is to provide an improved form of amplifier so constructed that the tone."J reproduced are of amplified volume, and at the same time devoid of harshness or mechanical sound.

ith these and other objects in view, as will appear as the description proceeds, the invention consists in the novel features of construction, combinations of elements and arrangements of parts, and hereinafter to be fully described and pointed out in the appended claims.

In the accompanying drawing:

Figure 1 is a longitudinal sectional view through the device.

Figure 2 is a sectional view on line 2 2 of Figure 1.

Referring to the drawing 1 designates a portion of a conventional form of talking machine cabinet provided with the usual throat 2, said throat being in communication with the tone arm structure (not shown). The lower end of the throat is fitted in a block 3, said block having a curved sound passage l formed therein.

A bracket 5 is mounted in the cabinet 1, and has associated therewith a screw 6 which engages the block 3 to hold the same properly positioned within the cabinet, there being a felt washer 7 carried by the screw to ab sorb any undue sound at this connection.

The main amplifier 8 is of bell shape and of sufcient length to have its front edge lic adjacent the front wall of the cabinet 1. The amplifier further comprises a plurality, preferably three in number, of auxiliary amplifiers 10, 11 and 12, which are substantially the same length but vary in diameter so that the adjacent ends thereof will be disposed in telescopic or nested annular spaced order, said auxiliary amplifiers be- 1923. Serial No. 643,770.

ing circular in cross section and of conical formation.

It will be apparent that the auxiliary amplifiers are so arranged as to not impede the flow of sound waves through the main amplifier 8, but result in increasing the resonance of the amplifier.

In order to hold the auxiliary amplifiers and main amplifier in proper spaced relation,bridge rings 13, 14, 15 and 16 are provided, the rings 16 being located to register with the passage 4 of the block 3 and is dis posed concentric with respect to the minor end of the amplifier 12, said ring being suitably secured to the flange 17 associated with the block 3. The rings 1li and 15 are each provided with annular webs 18, and resultant shoulders 19, which are engaged by the minor ends of the auxiliary amplifiers 10 and 11. The webs 18 are provided with passage-ways 2O and centering bridge pieces 21, the,bridge pieces of ring l'being engaged with the major end of the amplifier 11, while the major end of the amplifier 12 is engaged with the bridge pieces of ring 15. The ring 13 is likewise provided with passage-ways 21, and bridge pieces 22, said bridge pieces engaging the major end of the amplifier 10.

The rings may be secured to the inner surface of the amplifier 8 in any approved man ner, as will the auxiliary amplifiers to be secured to the respective rings. Itwill be observed that by arranging the rings as shown that resonant chambers 23, 24; and 25 are provided, the interior of which being open to the atmosphere through the respective auxiliary amplifiers.

It will be further observed that these rings serve to hold the main amplifier and auxiliary amplifiers in proper spaced relation, while the bridge pieces 20 and 21 hold the adjacent ends of the auxiliary amplifiers in spaced concentric relation.

It will be of course understood that the main amplifier as well as the auxiliary amplifiers are formed from material having sound resonant characteristics.

That is claimed is:

1. An amplifier for talking machines comprising a main amplifier, auxiliary amplifiers located therein and being of' hollow frusto conical formation, rings interposed between the walls of the main amplifier and the auxiliary amplifiers, said rings having sound passages and resonant bridge pieces,

10 auxiliary amplifiers, said rings having sound passages and resonant bridge pieces, the latter engaging the auxiliary ampliiciuto hold the same in spaced relation from each other and from the wall of the main amplifier7 said rings defining resonant chambers around the auxiliary amplifiers.

In testimony whereof I affix my signature.

CARL SCRABC. 

